trimble



N- PETERS, PHOTO-LITHOGRAPHER, WASHINGTON. D C,

i methodof arranging andapplying the force` derived from theiexpansionand contraction Isaac r.'rtniMBLE, or` LiviNGs'roiLNnw YORK'.-`

P. TRIMenIi, of

1. Livingston, ,county "off Columbia, and ,State of ewYork, haveinvented a new and useful Improvement" in VApparatus for `Operatinggthe`VentilatersffofApartmentsg` and I` dohereby declare thatqthe followingis a full, clear,and exaetldescription of the same, referencebeinginadeto the annexed drawa ings,;rnaking a which-e"r e a .A

i Figure I representsthemanner of arrang- `part of this "specification,in

dla-eram- .1 e ing thebands, .and Fig." isvan illustrative` M` invention,consists in.. an improved i of "metal, to the purposesofventilation andthe regulation, of temperature in apartments, e dwellings,conservatories, `graperi'es,` &c.

quite aware that the` mechanical force thus "derivedhasqbeen proposed`for the at-` ftainme'ntof 4these purposes, but so far as I``acquainted"with the` inode or` modes contemplated, thus far none haveproved suc-,y` l "cessfuhm'lhis arises chiefly"`from tliefact`thatathe"comparatively small motion obtained` `from fthe "expansion-barsby thef` or dinary changes of temperature inthe apart` e. ments togberegulated, was not sufficient to` bentilizedin` the opening` of 3valves&`c`. i. whereina considerable movement and power' is required.Inftheplan described by Ure forconstructing an apparatus forsimilar'purposes, of two bars of metal or other `materials of differenteXpansibility, `it has been found that the fcrce derived was not"suiiicient to eifectthe operation against the resistance producedfby soextended aleverage," and that thereforeall the power was absorbed ,inIsome way within the bars themselves oriin the play of the joints ofthelevers. 1 It `is of course readily understood that to render thefforcethus derived, useful, it must be capable of lapplication at j'verysmallchanges of temperature,`` the range perhaps not exceeding-ten orfteendegrees. Tendegrees is that withinjwhich I propose `employing thisforceyand in that the whole motion necessary for throwing` wide open orlcompletelyclosing asetof `valves, must be obtained from the extensionor contraction of the metal; Zinc is among the most eX-` `pansible ofmetals, yet in order to `attain aneXtension injlength `of one inch onlyby into consideration. obtaining the necessary motion,'I have also l""r"1aRArUs FOROPRATING vEirrILATons.-

e, sisciacaiinef Letters Permit` No.' 12,534, dated March 1s, 1855'.

ten degrees increase `of temperature, would Vrequiie apieceabout- 500feet long, and thu's itwill be seen" how smallmust be the movementfrompieces commonly available, when the Apower required is at the sametime taken `Besides the plan for one for the form of `tliejnietal bywhich it is intended to {secure sensitiveness and conse-` .quently"rapidity of motion with" strength.

Neither` round nor square bars would ac- .complish'this',` and thosewould be alsode-` ylicient in the necessary amount offlexibility, i 4Itherefore makegtheexpansion bars in the form of thinstrips or bands,- ofsuch variousr widths as will aifordthe power cir`cum` lstances mayrequire. By thismeans a large surface isexposed and thereby quicklyacted uponby changes of temperature. `The prinl cipalffeature howeverofmy invention is the manner of applying the power so as to get the mosti`extended direct ,motion with` the leastjrange of temperature. This maybejLinderstooool byan inspection ofL the diaf IgrainFig. II; in which A,"B`will 'represent crie of the metal bands'at lthefposition of 0 `when itis drawn into `a straight line, and supported" at thexends A BL Byraising the temperatura'the bandwill beextended, and if the supports AB` werekept immovable it would be deflected in some direction (as at A,C, B) by` anygiven extension'inv length,` Yas `say equal to from B toC.` Now if a weight were hung upon theband at B it would have moved over'the distance from iB to CV," whereas .had it'been by the directextension of thecordin a horizontal line it would have gone only ltotwice the distance from B to C. By doublingthis amount of expansion, asfrom A to D', the deflection is to D, and from A to E', is

`to F, &c., from which it will beseen that the ratio or distance frompoint to point in the deflection diminishes according to Well kno-wnlaws in geometry.` The most useful effect is therefore obtained by thefirst degrees of expansion, and these l accordingly use within thenarrow limits of temperature before named, `and to this end `a certainarrangement of the metal bands anda means of adjustment is necessary inorder that they shall begin to act at given temperatures. This will beapparent by, giving some dimensions to the diagram Fig. Il and supposinga certain extension of the cord; I give therefore the following, A, B iscalled 40 feet, or 240 inches from A to B. The distance from B to C byan eXpansion in the length A B of one inch will be as follows:

Or B to C will be fifteen m inches; in like manner by an extension oftwo inches, B to D will be twenty-one tg inches, and by an extension ofthree inches the distance B to E becomes twenty six T8671, inches. As nosuch extent of length as would give an expansion of one inch for tendegrees could conveniently be had, it becomes necessary to effect theobject by a different arrangement. This I do by combining together anumber of strips of the expansion bands, of such length as may beconveniently incased within a small frame, as may be seen in thedrawings at (a, a, a), the last one (a being that from which the poweris taken o. Now as before shown, the greatest range of motion ordeflection of the band by the least extent of expansion, is where itstarts from a horizontal or straight line, and I have therefore arrangedmy apparatus so that by means of a set-screw at one end of theexpansion-bars they can be tightened or set to begin to act at anyrequired temperature. Thus `suppose an apartment is to be kept at atemperature ranging between G0o and 70 F. I take up the stack of thebands (a a a) so that at that temperature of 60o F. the valves orVentilating-flaps will all be closed, and then regulate it so that at70o F. they will all be wide open. But in order to prevent accidents tothe bars by their contracting under an accidental reduction of thetemperature below 60 I provide a resisting spring atthe end opposite tothe screw, or the screw may be itself attached directly to the end ofthe spring, as will be more clearly shown by the following descriptionof the appa- VAt (e) is the adjusting screw before mentioned. This isattached to the side of the frame or other support and takes hold of theend ofthe first expansion band. At is the safety spring and is shown asattached Vto the terminating link of expansion bands.

At (a) is represented the band from which the power is taken off foroperating the ventilating door. It will now be seen that the spring (i)preserves the bands or other parts of the fastenings from risk ofbreakage should it happen that the screw (e) were turned so as to drawthe bands too tightly for action in case of contraction taking place bythe instrument being subjected to a lower temperature than was intended.The regulating screw also serves to enable the instrument to be set toopen or close the Vents at any required temperature.

I do not claim effecting the ventilation of buildings, &c., by operatingthe valves to the vents or air passages by the force derived from theexpansion of metal, as this has been before proposed, but

Vhat I do claim and desire to secure by Letters Patent is,

Having the valves or Ventilating doors connected to the said metal bandsabout midway between their fixed supports so that the varying degrees offlexure shall effect the operation of opening or closing said doors inthe manner and for the purpose herein described and shown.

Substantially as described.

I. P. TRIMBLE.

Witnesses:

I. P. PINssoN, S. H. MAYNARD.

